Estimating in situ Strength of Concrete Pavements under Various Field Conditions

摘要

During the past few years, the transportation industry has expressed the desire to create performance-based specifications. One of the key developments required to characterize and improve the performance of (PCC) pavements is a better understanding of its in situ properties. Of great importance is the accurate estimation of in situ concrete strength. There are currently many methods used to estimate in situ strength, each providing unique benefits. However, many of these techniques can introduce variables one that affect accurate estimation. Thus, a reevaluation of current procedures is required to appropriately reflect sound engineering principles and to produce a quality product. This project addresses many factors which arise in practice but whose effects on strength need to be determined, quantified, or reevaluated. These include the effects of core diameter, cylinder curing regime, pavement curing history, presence of reinforcement in a core, vertical location of core, aggregate type, and surface evaporation on both compressive and tensile strength. This project is different from previous research in that in situ strength is determined directly from tensile strength tests. If pavement strength is to be determined, it is suggested that indirect tensile tests should be conducted rather than estimating tensile strength from compressive or flexural tests, because of the fact that pavements fail in tension.